Radiation therapy in breast cancer: a narrative review on current standards and future perspectives

: Mastectomy and reconstructive procedures have been refined over the decades, allowing for aesthetic outcomes close to the native breast shape and in symmetry with the contralateral intact breast or even to improve breasts appearance and symmetry. Similarly, improvements in radiation oncology can help reduce treatment related toxicity and improve outcomes. However, postmastectomy radiation therapy (PMRT) is associated with poor cosmetic outcomes and increased rate complications in patients who undergo breast reconstruction. Radiation therapy planning should be guided by disease stage, risk of recurrence, correct definition of the target volumes and treatment objectives. Currently, there are guidelines endorsed by European Society for Radiotherapy and Oncology (ESTRO) for target volume delineation for breast cancer and elective nodal volumes, including after immediate reconstruction. Correct target volume delineation, along with meticulous radiation planning, total dose and fractionation, dose homogeneity, and organs at risk (OAR) doses are significant for reducing radiation-induced toxicity. Currently, tremendous efforts are done by different groups to improve aesthetic outcomes without compromising disease outcomes in breast cancer patients who are candidates for mastectomy and radiation therapy. The current paper summarizes key principles in PMRT, considering new surgical techniques for immediate breast reconstruction and new, partly experimental radiation techniques including future trials and proton beam irradiation.